Every time Severus sees those green eyes staring up at him he feels nauseated. Sometimes his gaze passes by with speed as he picks up his pace, stalking the classroom, and other times he forces himself to stare at the boy, defying every instinct of anger or denial, reducing it down to a questioning attitude.

Those green eyes are bright with life, just like hers, but if he would take the time to think upon it, to look a bit longer without any malice in his mind, he'd see they are subtly duller - a symptom of a life intrinsically dragged down. He'd believe it if he allowed himself to think it, because of course nothing good truly came of all that went on back then, not in his mind. Harry Potter is as burdened and damaged as Severus is but he'd rather not see it, there's enough pain he's caused as it is without accepting responsibility for more.

Instead he considers Harry a less-than-innocent byproduct of his failed past, the son Lily had, who should have been his, but wasn't. That bites, and to have it be James Potter who won her over, to have Potter's son challenging all that is, proudly stamped as his father's, is infuriating. The only reminder of her is those eyes and looking at them brings it all back, like a knife from behind, the betrayal burning and, for the most part, he knows it was his fault, his mistakes that made this world. What settles that feeling, helping him wrestle the emotions and put his internal mask in place, is knowledge - Severus knows it can't be better than this, merely differently damaged. He doesn't believe in fate, he simply knows, despite wishing for a past that wouldn't haunt him, that this reality is no more or less nightmare-ish than any other.

Hands move over the smooth jet black leather cover, flicking across the silver edging with some satisfaction before he dampens the inappropriate enjoyment. Standing seriously, upright and eagle eyed, in the comfort of his quarters, he cracks open the book. He bristles at the idea of comfortable though, the word passing through his head sounds wrong. He, a teacher at Hogwarts and, not so long ago, a suspected Death Eater facing Azkaban, delving into dark arts once more...it should be harder, he feels. It is one year since Voldemorts downfall and they are too elated it seems, not nearly wary enough to indicate having learnt their lesson.

He's used to dark and dank dens, more hurried affairs, co-conspirators with devilish grins and wicked eyes watching him for a chance to deride as much as to witness. What he's about to do probably breaks numerous laws, not simply magical ones either (Muggles didn't get everything wrong with their science after all), and yet the candles burn steadily, owls hoot in the distance and nobody can tell. Even under the nose of Albus Dumbledore, he can do this and it bothers him in a way the Dark Arts never have before.

Taking four vials off the sideboard, he measures out the quantities and pours them slowly into the Pensieve. The text instructs one stir widdershins and rolling of the vessel, and hence liquid, five times in the natural direction, and Severus hopes the writer wasn't of a non-standard mindset and the meaning of which direction is which - five month's salary went into this experiment, despite the ridicule of his ragged robes. Holding his breath he waits until it turns white before dropping the final ingredient in, a splinter of already burnt willow wood. With a flash of silver it is done and the liquid is as clear as water, his distorted reflection marring the surface, a picture flawed even more by the charred black bottom of the Pensieve. Tonight's work is done; it is time to begin the search.

He almost wishes someone would break the door down, just come in and hex him, prevent this foolishness. The motivation for doing this, he knows, is a dangerous one, curiosity is not a balanced reason when it comes to such serious matters. Yet he cannot stop as that sense of wonder he's managed to keep battened down for so many years resurfaces, overwhelming the grief for a brief time at least and it feels good to have a purpose again. Out there somewhere is a better world and he intends to bend this one to it - he will right his wrongs and never need redemption. All their mistakes can be undone.

His senses fall into a whirlwind, a spin that is slowed and a blur that is focused with great concentration. Scenes pass him by like flittering pictures he is dipping into as he forces change on the world. Skipping back and forth throughout the years he finds a sight in this potential life that is familiar, but wrong enough to catch his attention. The playground, in an autumn come early since he sees his younger, correction 'other', self still there, not yet escaped to Hogwarts. It is a curious feeling to be looking at a past that is not his and, quite unlike any other pensieve, is not another's but that of a boy that would be him if not for a few minor details.

The setting grabs his attention because he is older here than he ever remembers being in this place. A few years younger and it would have been a place of small joys, the setting for a friendship he'd cherished. But here he is old enough to be bitter about them and, as he follows his 'other' figure, the fear seeps in to find a teenage girl with long red locks idling on a swing, her back to both of them.

She pushes off from the ground, the seat carving a small arc in the air, but makes no attempt to carry the momentum. Finally she comes to a stop again, faces him over her shoulder with eyes that look inflamed, the skin around them red and a passion in them that suddenly makes him blanche. There's a hate inside her, directed through him to the other him, the boy she seems to know.

"Severus."

"Lily."

One-word exchanges; hers cold and hot at the same time and his uncharacteristically soft, as if begging for forgiveness.

"You're not off yet then?" she asks, turning away from him as she does. Her voice edges on normal for that moment and she starts to swing, feigning a casual conversation and an attitude of nonchalance in stark contract to her previous reaction to his arrival.

"I leave tomorrow morning."

"Hmm, sixteen hours and counting. Lucky you."

"I almost wish you could come -"

"But you don't, do you? It's too dangerous, political turmoil you say. Muggle-borns aren't wanted even if they can do magic, are they? No one would want me there; I'm as good as a squib. I'd have to take catch up classes once I leave home, if they do that sort of thing, but I'm guessing not and, besides, I plan to go places, travel."

There's the flash of passion as she briefly looks around at the younger him, eyes green with a malicious jealousy and the unspoken promise - I'm going to leave you behind like you left me. Lily isn't going to Hogwarts this year and Severus wonders if she ever has. The jealousy she shows is unnerving. He'd seen Lily Evans angry but never like this, perversely it makes his heart race to see the fight in her, the desire for magic and the desire to share it with him, and yet he knows this isn't the one, a world where they are divided. She's out of harms way in the worst possible way, this isn't what she'd want and it isn't how he wants it to be.

The second reality he ventures into, the next evening, gets off to a sickening start. His heart sinks to the depths of his stomach, watching that dreadful scene in his fifth year where he had alienated Lily, shunned her with the shameful insult she could never deserve and yet, re-watching it in the alternate Pensieve, the other him doesn't say it. Severus feels a glimmer of triumph, this was where they diverged, and believing for a second this change may fix it. He eagerly scans the years after that, all seems hopeful.

Lily is by his side throughout much of them but in the end things turn out no different - he is lured by his friends to the Dark Arts ever more, causing conflict between them, and James Potter still charms Lily away, much to his dismay. It's like he never mattered enough to her, never meant anything more. He emerges from the illusion furious and knocks over the Pensieve in a fit of uncharacteristic violence - Severus has known rages all his life as a belittled boy and troubled teen, yet he rarely lashes out physically, it being too much a taboo in his mind, a reminder of his past and the man he cannot stand. Maybe he has become as bad as his father, despite the magic - the carefully wound restraint is gone tonight. Flagstones shimmer in the moonlight as he casts open the curtains, flinging the windows open only a little less dramatically.

It is a another five years before he approaches the project again. He'd carefully reevaluated the benefits and considered the misery of searching more than made up for in the end result, presuming he was successful - and Severus isn't used to failure, doesn't allow for it.

What he stumbles on is unexpected. A dark room, illuminated by merely candelight where he and Lily, young enough to be only just out of Hogwarts, lounge on a bed as if in the lap of luxury - certainly neither of their family homes. It's hard to see details in the dim light yet he recognises the style, decadent and silken, smooth lines abstracted by bold woods and strutting silver. Slytherin at heart, undoubtedly the Malfoy mansion. Why would they be there of all places?

Lily moves her leg closer to Severus on the bed, settling it over her other outstretched limb, causing her robes to hitch up.

"Thank you for letting me go, Severus," she says gratefully, eyes staring into the young man's.

The younger Severus coughs nervously, clearly out of his element with her. "It's only for tonight remember, Lily. I don't hold as much sway as you might think. You're still a prisoner."

"I note you don't say 'our' prisoner."

And Lily studies him briefly, though it's unclear just why that detail matters to her so when he is evidently not going to let her escape - his wand is within reach, a protective charm placed around it that only he would be able to get through. Eventually she turns away, perhaps unable to find what she was looking for. He curses the fact he can't use Legilimency here, and then wonders suspiciously if she might have been doing so herself.

"Still, it's nice to have the shackles off and good of you to try and heal the cuts from them."

"Medimagic was never my speciality," the young Death Eater retorts dryly.

Then comes the picture, the scene, the moment that had made his mouth go dry when he had spied the almost-memory. There's a not so subtle shift towards him and parted lips, eyes closed like a statue of a sleeping angel, face carved with as much grace. She looks pure and gentle, porcelain skin framed by her red hair and this time the moment is not frozen. Lily continues, hand tilting his chin up and lips pressing down hard. Passion explodes and she kisses with a fever, pressured contact that she will not break, one hand curling in his hair and the other snaking against his back, bringing him completely against her and under a special kind of spell.

This lustful scene was once a dream and here he sees it played out in front of him, making him forget the circumstance and rejoice in having returned to find this. Gradually it escalates into something less and less expected from Lily, her hand now gripping his neck hard enough for her nails to dig in, drawing blood. Fear sparks in boy when it becomes apparent he cannot stop this, he's lost control of the situation and it's less than a minute later that Severus watching realises why. As she lets go of him, he spasms, coughing grotesquely and groping for his wand he grows weaker. Fingers claw at the bedstead, managing to grip the slender piece of wood, only for Lily to grab his arm and pry it out of them with little resistance.

The blood stains his lips, warning of his impending fate. She straddles him though, peering down, face to face.

"Finally we are equal."

The view fades to black; Severus doesn't stay to see the end, doesn't want to know what he had done to deserve such treatment. The contrast of what he seeks and what he finds shocks him and his own memory is marred by hatred, knowing she would, could, do that to him. But he does not give up, his skin is thicker than the last time. He simply retires to bed and blocks out his dreams.

Night after night, locked in his rooms, he plunges himself into a dreamscape of realities, looking fervently for a happy ending that he can't really imagine. Each world seems familiar, a trick of the light, but scratching the surface he always find the differences and soon enough the imperfections become clear. They all diverged from his at some significant point in his life or hers.

The most surprising reality is the one where she does not die that fateful night. He'd still foolishly told Voldemort the prophecy, Peter Pettigrew had still squealed like the rat he was, but Lily had returned with Harry to the headquarters. He would never know why or how it came to be but there it was, they lived.

Lily Potter stood in the circle naked, surrounded by Death Eaters, humiliated, and pledged herself, her son, to the Dark Lord. She screamed as they branded her with the Dark Mark and, again, when she was punished for weakness. Screams that lingered into the night until she learnt to stifle them for her own good. In amongst the crowd, both Severus's watched, at least one of them mortified by this turn of events. A lot of horrific things had happened in front of him but none of them twisted his gut quite like seeing the woman he loved commit herself to what must be her living hell.

This reality he returned to each evening for a week, trying to unfold its secrets and decide its worth. What would happen? Did he save her? Did he take her under his wing and shelter her from the worst of it?

Somehow he doubted any of that. However, he had to see for himself, the accident unfolding and damage hard to tell before it is over.

Monday had her practising the Unforgivables with Grutsquall, who was notoriously unforgiving and wouldn't hesitate to retaliate for each mistake. His counterpart merely watched as she fell down over and over, tears leaking out despite her best attempts to hide the pain. At the end, when Grutsquall was adequately satisfied she found her voice once more.

"Show me my son now."

Demanding it. Becoming one of them, because asking would get her nowhere and she will do anything for Harry. She would have died. Why didn't she? He will likely never find out.

Tuesday, she stood next to him, the other him. This was not out of sentiment, he could recognise well enough that he must've been ordered to pay attention to her movements. Who made a better spy than an old friend? But Voldemort never understood the fragile nature of friendship and her gaze did nothing more than pass over the accompanying Severus, deemed invisible. Shunned just as he had done her once. All too quickly she was adopting behaviours that denoted hate in her heart. He knew this wouldn't work as a choice but still he kept on coming back.

Wednesday was potions class, of the darkest brew possible. Their figures huddled over a cauldron, no doubt creating a highly illegal substance. They worked in silence, yet attained a working companionship that was enviable but when the ingredients were all gone and the liquid stoppered, Lily walked away dejectedly - duty done.

On Thursday she held up her son, an offering to the Dark Lord. Harry Potter was finally marked. No lightning scar, instead the dark mark - the threat vanquished supposedly. She was commanded to sit with the boy on her lap, at his very side. Lily cried silently, the water rolling down her face, a dark imitation of the Madonna. A smile falls on Voldemort's slick mouth and they feast, raising glasses high.

Friday shows him years later, a mother warily watching her son 'play' with the other boys of the circle - they're casting nastier hexes than he'd known at twice their age but she doesn't bat an eyelid. Her Severus hovers at the edge of the arena and, finally, after several minutes of denial, she addresses him.

"Come to judge him have you, Severus? Want to know if he's worthy?"

She doesn't say what for, it's an implied piece of information that's he as a watcher is missing.

"Worthiness hardly concerns me...Lily."

Her name is a cautious addition, a personal identification in an already tricky statement and she full well knows how vulnerable it makes him to say it. Nevertheless, she glares at him in return.

"Better not let him catch you saying such things. He'll have your head on a stick."

"Pike, I think you'll find. And no, the Dark Lord doesn't go for that sort of thing."

"Really? I could have sworn otherwise."

At that Lily laughs, with a slight hysteria. A dual edged emotion expressed, almost relish at winning the challenge of superiority that everyone among them must battle for, coupled with a casualness at killing, and yet also a despair to be thinking of any of it at all.

The Severus in front of her scowls and raises an eyebrow. Used to her antics, accepting them for what they are. But he himself, he can't accept it, watching from a world that knew none of this.

A redheaded woman laughs and laughs at him, gasping for breath. She isn't Lily anymore. He's sure Voldemort has estimated wrongly, Harry is the key and it will all fall in the end, but he no longer cares for this reality, devoid of love. She gave everything in herself to save him, died a bit day in and day out, all the love used up, vengeance taking its place. Harry won't be better off here than with the Muggles and Lily is long gone and lost to him.

The search continues on, in bursts of forty days straight. Year after year, trudging through endless trees of life. The year Harry joins Hogwarts is when it starts to fall at the wayside, his other duties returning. Every year he manages a a few short stints but has nowhere near as much attention for it as he once did. When Dumbledore tells him he'll be giving Harry private Occlumency lessons, he's more than irritated as the further intrusion into this.

What he sees shortly before those lessons does not help him stem the emotion at the painful reminder Harry is. It is only fuel on the fire, the cause of the unwarranted remarks that he utters in the boy's presence. Suddenly Severus really remembers how it felt. The hope flickers out, replaced by a shameful anger.

Severus spies the worst version of himself. The boy who didn't turn back from 'Mudblood' but carried on once spurned, hounding Lily. Frequent trips to the infirmary, because of course Potter and co. meted out punishment. Undeterred, he grew more cruel with each reminder that she'd drifted across into Potter's arms and it seemed that it hardly mattered that he'd pushed her into them. There was no sign of guilt or remorse, simply a passionate fury directed at her alone.

That Severus joined forces with the Death Eaters, more as an afterthought to his personal mission of torturing her, than for any other reason - a single ambition easily fulfilled. He made sure she knew, met up with her especially under the guise of an apology. Expecting reconciliation of a sort, she came only to be dealt a further blow.

The crazed boy had grinned cruelly at her agape mouth and for some bizarre reason she'd still anguished at the knowledge of her friend's decision, even after years of jibes and jabs from him.

"Why do you do this to yourself, Sev? What happened to you?"

Something snaps then and there, evident in his change to a purely cold expression and his sharply simple answer.

"You did."

The next time she sees the Severus of her world, he is as cold as that day and bathed in green light. Ironically, impeccably mannered as always, he interrupts the wedding ceremony in the correct section for objections.

Severus watches the young Lily weep over the body of James Potter and, when she has no more tears left, she beats the murderer of her fiance.

He'd often wondered what was the worst choice he'd made - calling her a Mudblood, sticking by his Slytherin 'friends', or reporting the prophecy overheard. Here he's made far worse. The darkest vengeful desire of his is fulfilled and he sees it, feels it, near as lives it and is ashamed to not feel as horrified as he would think.

He'd killed for her as a double agent, she'd never know that the thought of her was what kept him going after he'd gotten in too deep, she was the strength where he was the coward and he forced himself to carry on because he didn't wish to feel more ashamed than he already did at his own foolish choices. Harry is where his choices got him. Guessing Dumbledore is aware of his pastime, he imagines the head teacher wishes him to give up, and what better than Harry bleedin' Potter to show him how close they are to ending it here, now - without Lily.

The last reality, the last possible world he had investigated, was one in which he was mad.

There were flowers at the bedside, meadows flowers that remind him of his childhood and the few carefree days spent roaming what little countryside there was near where he'd live. For such flowers they were kept remarkably fresh, excellent charm at work there. Lily's infact.

She perched on an uncomfortable armchair, unconsciously preening herself, her watchful eyes taking in everything around her. Public ward. A flimsy screen. No privacy. Barest necessities, the vase was brought in, homemade with chubby fingerprint impressions and garish colours.

There are two silhouettes on the curtain, a child and a man, he presumes. James and Harry, James' foot tapping impatiently as Lily stumbles for words.

The grey-haired person in the bed is frantically counting his own fingers. He seems withered, aged beyond his years, but Severus still recognises himself in the patient.

She draws up a tray from the box she brought and watches him brew a little 'potion' - completely harmless ingredients given, nothing more than a child's toy but he believes, there's still genius at work there. He mumbles something about mixing Verbane with Dragon's blood anti-clockwise but doesn't finish.

"To stop the explosive effect?" she concludes. There is no reply, yet she smiles brightly and says she'll mention his idea to Miranda, a friend who works at Smilding's Potions. She smiles again, corners of her eyes crinkling, and covers his hand with hers. All she gets in return is a blank stare, prompting her to look away. A tad more absentminded fiddling with her hair and she rises, collects her bag and leaves him be.

On the other side of the curtain she meets scorn as she prepares to exit.

"Why do you waste your time on him?" asks Potter defiantly.

On the surface Potter surely means why bother with someone who can't tell who you are, but it's implied as strongly why do you care about Snape, slithering Slytherin that he is.

"He doesn't have anyone else."

True as that is, it sounds a weak reason, and her voice falters, either recognising this or from distress at the questioning.

"But he doesn't know who you are. You know how it is with this torture, you've seen plenty of victims. He won't remember you visited!"

"I will."

She finds strength with those words and it is she who takes Harry's hand, decidedly moving out of range before a pointless retaliation, leaving James Potter stupidly standing there with no answer.

For a minute after she's left Severus watches this cracked version of himself and wonders if oblivion would be worth it, not knowing her love but at least here she doesn't hate him and he can see it isn't pure pity that brings her back - she's a friend again, he'd never know in this reality but he does now and he considers it carefully. Oddly enough this is best reality he's located so far. Lily is happy, she has a family and he would never know anything other than a life of simplicity, of a woman who sits and smiles beautifully at him.

It is that last reality that he thinks back to when he is dying. Harry's green eyes peer down at him with an unidentifiable emotion present, one that is at least not the hatred of these past few years, and it brings the doubts to mind - he will not live to see the end of this war and he could neither stop it nor prevent his own mistakes, he couldn't find a better world because there probably isn't one apart from the one he's grudgingly helped make, should Harry succeed.

What comes next, as the colour fades, is the closest thing to it - another hell perhaps, heaven unlikely or an oblivion that may as well be anyone of the countless possibilities for the difference it makes. Finally it is over, everything meaningless, and yet Severus is content he tried, glad to have known her, loved her, to the bitter end. Lily was one constant that defined his world, regardless of what went on - a love that hurt, going hand in hand with pain and misery, torture.